1. Field of the Invention
The present invention relates to a field-effect organic transistor, more specifically a field-effect organic transistor useful for the electronic devices, e.g., displays, information tags and ICs.
2. Related Background Art
An organic transistor which utilizes an organic semiconductor can be formed on a plastic substrate and into a large picture plane, while a silicon transistor has difficulty in this regard, and has been increasingly expected to apply to new devices, e.g., flexible electronic paper and information tags.
An organic semiconductor produced by a vacuum evaporation process is disclosed by Japanese Patent Application Laid-Open No. 2001-094107, and an organic semiconductor produced by a liquid-phase process is disclosed by U.S. Pat. No. 6,107,117.
However, the organic semiconductors proposed so far have a disadvantage of a low mobility, limited to the order of 10−1 cm2/Vs for production by vacuum evaporation process, and 10−2 cm2/Vs for production by a liquid-phase process. Other problems involved in organic transistors are a high threshold voltage and fluctuation of a threshold voltage in driving for a long period. Few organic transistors have been commercialized because of these problems.
The present invention has been accomplished to solve these problems in the conventional techniques. It is an object of the present invention to provide a new field-effect organic transistor having an organic semiconductor layer for solving the problems of the prior art.